Commit | Line | Data |
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6a55d2cd | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 LT |
2 | /* |
3 | * Xpram.c -- the S/390 expanded memory RAM-disk | |
4 | * | |
5 | * significant parts of this code are based on | |
6 | * the sbull device driver presented in | |
7 | * A. Rubini: Linux Device Drivers | |
8 | * | |
9 | * Author of XPRAM specific coding: Reinhard Buendgen | |
10 | * buendgen@de.ibm.com | |
11 | * Rewrite for 2.5: Martin Schwidefsky <schwidefsky@de.ibm.com> | |
12 | * | |
13 | * External interfaces: | |
14 | * Interfaces to linux kernel | |
15 | * xpram_setup: read kernel parameters | |
16 | * Device specific file operations | |
17 | * xpram_iotcl | |
18 | * xpram_open | |
19 | * | |
20 | * "ad-hoc" partitioning: | |
21 | * the expanded memory can be partitioned among several devices | |
22 | * (with different minors). The partitioning set up can be | |
23 | * set by kernel or module parameters (int devs & int sizes[]) | |
24 | * | |
25 | * Potential future improvements: | |
26 | * generic hard disk support to replace ad-hoc partitioning | |
27 | */ | |
28 | ||
d1c2f892 MS |
29 | #define KMSG_COMPONENT "xpram" |
30 | #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt | |
31 | ||
1da177e4 LT |
32 | #include <linux/module.h> |
33 | #include <linux/moduleparam.h> | |
34 | #include <linux/ctype.h> /* isdigit, isxdigit */ | |
35 | #include <linux/errno.h> | |
36 | #include <linux/init.h> | |
1da177e4 LT |
37 | #include <linux/blkdev.h> |
38 | #include <linux/blkpg.h> | |
39 | #include <linux/hdreg.h> /* HDIO_GETGEO */ | |
edbaa603 | 40 | #include <linux/device.h> |
1da177e4 | 41 | #include <linux/bio.h> |
14532095 MH |
42 | #include <linux/suspend.h> |
43 | #include <linux/platform_device.h> | |
5a0e3ad6 | 44 | #include <linux/gfp.h> |
7c0f6ba6 | 45 | #include <linux/uaccess.h> |
1da177e4 LT |
46 | |
47 | #define XPRAM_NAME "xpram" | |
48 | #define XPRAM_DEVS 1 /* one partition */ | |
49 | #define XPRAM_MAX_DEVS 32 /* maximal number of devices (partitions) */ | |
50 | ||
1da177e4 LT |
51 | typedef struct { |
52 | unsigned int size; /* size of xpram segment in pages */ | |
53 | unsigned int offset; /* start page of xpram segment */ | |
54 | } xpram_device_t; | |
55 | ||
56 | static xpram_device_t xpram_devices[XPRAM_MAX_DEVS]; | |
57 | static unsigned int xpram_sizes[XPRAM_MAX_DEVS]; | |
58 | static struct gendisk *xpram_disks[XPRAM_MAX_DEVS]; | |
3ce66093 | 59 | static struct request_queue *xpram_queues[XPRAM_MAX_DEVS]; |
1da177e4 LT |
60 | static unsigned int xpram_pages; |
61 | static int xpram_devs; | |
62 | ||
63 | /* | |
64 | * Parameter parsing functions. | |
65 | */ | |
0c0db035 MS |
66 | static int devs = XPRAM_DEVS; |
67 | static char *sizes[XPRAM_MAX_DEVS]; | |
1da177e4 LT |
68 | |
69 | module_param(devs, int, 0); | |
5c898ba9 | 70 | module_param_array(sizes, charp, NULL, 0); |
1da177e4 LT |
71 | |
72 | MODULE_PARM_DESC(devs, "number of devices (\"partitions\"), " \ | |
73 | "the default is " __MODULE_STRING(XPRAM_DEVS) "\n"); | |
74 | MODULE_PARM_DESC(sizes, "list of device (partition) sizes " \ | |
75 | "the defaults are 0s \n" \ | |
76 | "All devices with size 0 equally partition the " | |
77 | "remaining space on the expanded strorage not " | |
78 | "claimed by explicit sizes\n"); | |
79 | MODULE_LICENSE("GPL"); | |
80 | ||
1da177e4 LT |
81 | /* |
82 | * Copy expanded memory page (4kB) into main memory | |
83 | * Arguments | |
84 | * page_addr: address of target page | |
85 | * xpage_index: index of expandeded memory page | |
86 | * Return value | |
87 | * 0: if operation succeeds | |
88 | * -EIO: if pgin failed | |
89 | * -ENXIO: if xpram has vanished | |
90 | */ | |
91 | static int xpram_page_in (unsigned long page_addr, unsigned int xpage_index) | |
92 | { | |
94c12cc7 | 93 | int cc = 2; /* return unused cc 2 if pgin traps */ |
1da177e4 | 94 | |
94c12cc7 MS |
95 | asm volatile( |
96 | " .insn rre,0xb22e0000,%1,%2\n" /* pgin %1,%2 */ | |
97 | "0: ipm %0\n" | |
98 | " srl %0,28\n" | |
1da177e4 | 99 | "1:\n" |
94c12cc7 MS |
100 | EX_TABLE(0b,1b) |
101 | : "+d" (cc) : "a" (__pa(page_addr)), "d" (xpage_index) : "cc"); | |
1da177e4 LT |
102 | if (cc == 3) |
103 | return -ENXIO; | |
8df22b4b | 104 | if (cc == 2) |
1da177e4 | 105 | return -ENXIO; |
8df22b4b | 106 | if (cc == 1) |
1da177e4 | 107 | return -EIO; |
1da177e4 LT |
108 | return 0; |
109 | } | |
110 | ||
111 | /* | |
112 | * Copy a 4kB page of main memory to an expanded memory page | |
113 | * Arguments | |
114 | * page_addr: address of source page | |
115 | * xpage_index: index of expandeded memory page | |
116 | * Return value | |
117 | * 0: if operation succeeds | |
118 | * -EIO: if pgout failed | |
119 | * -ENXIO: if xpram has vanished | |
120 | */ | |
121 | static long xpram_page_out (unsigned long page_addr, unsigned int xpage_index) | |
122 | { | |
94c12cc7 | 123 | int cc = 2; /* return unused cc 2 if pgin traps */ |
1da177e4 | 124 | |
94c12cc7 MS |
125 | asm volatile( |
126 | " .insn rre,0xb22f0000,%1,%2\n" /* pgout %1,%2 */ | |
127 | "0: ipm %0\n" | |
128 | " srl %0,28\n" | |
1da177e4 | 129 | "1:\n" |
94c12cc7 MS |
130 | EX_TABLE(0b,1b) |
131 | : "+d" (cc) : "a" (__pa(page_addr)), "d" (xpage_index) : "cc"); | |
1da177e4 LT |
132 | if (cc == 3) |
133 | return -ENXIO; | |
8df22b4b | 134 | if (cc == 2) |
1da177e4 | 135 | return -ENXIO; |
8df22b4b | 136 | if (cc == 1) |
1da177e4 | 137 | return -EIO; |
1da177e4 LT |
138 | return 0; |
139 | } | |
140 | ||
141 | /* | |
142 | * Check if xpram is available. | |
143 | */ | |
14532095 | 144 | static int xpram_present(void) |
1da177e4 LT |
145 | { |
146 | unsigned long mem_page; | |
147 | int rc; | |
148 | ||
149 | mem_page = (unsigned long) __get_free_page(GFP_KERNEL); | |
150 | if (!mem_page) | |
151 | return -ENOMEM; | |
152 | rc = xpram_page_in(mem_page, 0); | |
153 | free_page(mem_page); | |
154 | return rc ? -ENXIO : 0; | |
155 | } | |
156 | ||
157 | /* | |
158 | * Return index of the last available xpram page. | |
159 | */ | |
14532095 | 160 | static unsigned long xpram_highest_page_index(void) |
1da177e4 LT |
161 | { |
162 | unsigned int page_index, add_bit; | |
163 | unsigned long mem_page; | |
164 | ||
165 | mem_page = (unsigned long) __get_free_page(GFP_KERNEL); | |
166 | if (!mem_page) | |
167 | return 0; | |
168 | ||
169 | page_index = 0; | |
170 | add_bit = 1ULL << (sizeof(unsigned int)*8 - 1); | |
171 | while (add_bit > 0) { | |
172 | if (xpram_page_in(mem_page, page_index | add_bit) == 0) | |
173 | page_index |= add_bit; | |
174 | add_bit >>= 1; | |
175 | } | |
176 | ||
177 | free_page (mem_page); | |
178 | ||
179 | return page_index; | |
180 | } | |
181 | ||
182 | /* | |
183 | * Block device make request function. | |
184 | */ | |
dece1635 | 185 | static blk_qc_t xpram_make_request(struct request_queue *q, struct bio *bio) |
1da177e4 | 186 | { |
74d46992 | 187 | xpram_device_t *xdev = bio->bi_disk->private_data; |
7988613b KO |
188 | struct bio_vec bvec; |
189 | struct bvec_iter iter; | |
1da177e4 LT |
190 | unsigned int index; |
191 | unsigned long page_addr; | |
192 | unsigned long bytes; | |
1da177e4 | 193 | |
af67c31f | 194 | blk_queue_split(q, &bio); |
54efd50b | 195 | |
4f024f37 KO |
196 | if ((bio->bi_iter.bi_sector & 7) != 0 || |
197 | (bio->bi_iter.bi_size & 4095) != 0) | |
1da177e4 LT |
198 | /* Request is not page-aligned. */ |
199 | goto fail; | |
4f024f37 | 200 | if ((bio->bi_iter.bi_size >> 12) > xdev->size) |
1da177e4 LT |
201 | /* Request size is no page-aligned. */ |
202 | goto fail; | |
4f024f37 | 203 | if ((bio->bi_iter.bi_sector >> 3) > 0xffffffffU - xdev->offset) |
1da177e4 | 204 | goto fail; |
4f024f37 | 205 | index = (bio->bi_iter.bi_sector >> 3) + xdev->offset; |
7988613b | 206 | bio_for_each_segment(bvec, bio, iter) { |
1da177e4 | 207 | page_addr = (unsigned long) |
7988613b KO |
208 | kmap(bvec.bv_page) + bvec.bv_offset; |
209 | bytes = bvec.bv_len; | |
1da177e4 LT |
210 | if ((page_addr & 4095) != 0 || (bytes & 4095) != 0) |
211 | /* More paranoia. */ | |
212 | goto fail; | |
213 | while (bytes > 0) { | |
214 | if (bio_data_dir(bio) == READ) { | |
215 | if (xpram_page_in(page_addr, index) != 0) | |
216 | goto fail; | |
217 | } else { | |
218 | if (xpram_page_out(page_addr, index) != 0) | |
219 | goto fail; | |
220 | } | |
221 | page_addr += 4096; | |
222 | bytes -= 4096; | |
223 | index++; | |
224 | } | |
225 | } | |
4246a0b6 | 226 | bio_endio(bio); |
dece1635 | 227 | return BLK_QC_T_NONE; |
1da177e4 | 228 | fail: |
6712ecf8 | 229 | bio_io_error(bio); |
dece1635 | 230 | return BLK_QC_T_NONE; |
1da177e4 LT |
231 | } |
232 | ||
a885c8c4 | 233 | static int xpram_getgeo(struct block_device *bdev, struct hd_geometry *geo) |
1da177e4 | 234 | { |
1da177e4 | 235 | unsigned long size; |
a885c8c4 | 236 | |
1da177e4 LT |
237 | /* |
238 | * get geometry: we have to fake one... trim the size to a | |
239 | * multiple of 64 (32k): tell we have 16 sectors, 4 heads, | |
240 | * whatever cylinders. Tell also that data starts at sector. 4. | |
241 | */ | |
1da177e4 | 242 | size = (xpram_pages * 8) & ~0x3f; |
a885c8c4 CH |
243 | geo->cylinders = size >> 6; |
244 | geo->heads = 4; | |
245 | geo->sectors = 16; | |
246 | geo->start = 4; | |
1da177e4 LT |
247 | return 0; |
248 | } | |
249 | ||
83d5cde4 | 250 | static const struct block_device_operations xpram_devops = |
1da177e4 LT |
251 | { |
252 | .owner = THIS_MODULE, | |
a885c8c4 | 253 | .getgeo = xpram_getgeo, |
1da177e4 LT |
254 | }; |
255 | ||
256 | /* | |
257 | * Setup xpram_sizes array. | |
258 | */ | |
259 | static int __init xpram_setup_sizes(unsigned long pages) | |
260 | { | |
261 | unsigned long mem_needed; | |
262 | unsigned long mem_auto; | |
f257b063 | 263 | unsigned long long size; |
7e2e2b96 | 264 | char *sizes_end; |
1da177e4 LT |
265 | int mem_auto_no; |
266 | int i; | |
267 | ||
268 | /* Check number of devices. */ | |
269 | if (devs <= 0 || devs > XPRAM_MAX_DEVS) { | |
d1c2f892 | 270 | pr_err("%d is not a valid number of XPRAM devices\n",devs); |
1da177e4 LT |
271 | return -EINVAL; |
272 | } | |
273 | xpram_devs = devs; | |
274 | ||
275 | /* | |
276 | * Copy sizes array to xpram_sizes and align partition | |
277 | * sizes to page boundary. | |
278 | */ | |
279 | mem_needed = 0; | |
280 | mem_auto_no = 0; | |
281 | for (i = 0; i < xpram_devs; i++) { | |
f257b063 | 282 | if (sizes[i]) { |
7e2e2b96 SO |
283 | size = simple_strtoull(sizes[i], &sizes_end, 0); |
284 | switch (*sizes_end) { | |
f257b063 HC |
285 | case 'g': |
286 | case 'G': | |
287 | size <<= 20; | |
288 | break; | |
289 | case 'm': | |
290 | case 'M': | |
291 | size <<= 10; | |
292 | } | |
293 | xpram_sizes[i] = (size + 3) & -4UL; | |
294 | } | |
1da177e4 LT |
295 | if (xpram_sizes[i]) |
296 | mem_needed += xpram_sizes[i]; | |
297 | else | |
298 | mem_auto_no++; | |
299 | } | |
300 | ||
d1c2f892 | 301 | pr_info(" number of devices (partitions): %d \n", xpram_devs); |
1da177e4 LT |
302 | for (i = 0; i < xpram_devs; i++) { |
303 | if (xpram_sizes[i]) | |
d1c2f892 MS |
304 | pr_info(" size of partition %d: %u kB\n", |
305 | i, xpram_sizes[i]); | |
1da177e4 | 306 | else |
d1c2f892 MS |
307 | pr_info(" size of partition %d to be set " |
308 | "automatically\n",i); | |
1da177e4 | 309 | } |
d1c2f892 MS |
310 | pr_info(" memory needed (for sized partitions): %lu kB\n", |
311 | mem_needed); | |
312 | pr_info(" partitions to be sized automatically: %d\n", | |
313 | mem_auto_no); | |
1da177e4 LT |
314 | |
315 | if (mem_needed > pages * 4) { | |
d1c2f892 | 316 | pr_err("Not enough expanded memory available\n"); |
1da177e4 LT |
317 | return -EINVAL; |
318 | } | |
319 | ||
320 | /* | |
321 | * partitioning: | |
322 | * xpram_sizes[i] != 0; partition i has size xpram_sizes[i] kB | |
323 | * else: ; all partitions with zero xpram_sizes[i] | |
324 | * partition equally the remaining space | |
325 | */ | |
326 | if (mem_auto_no) { | |
327 | mem_auto = ((pages - mem_needed / 4) / mem_auto_no) * 4; | |
d1c2f892 MS |
328 | pr_info(" automatically determined " |
329 | "partition size: %lu kB\n", mem_auto); | |
1da177e4 LT |
330 | for (i = 0; i < xpram_devs; i++) |
331 | if (xpram_sizes[i] == 0) | |
332 | xpram_sizes[i] = mem_auto; | |
333 | } | |
334 | return 0; | |
335 | } | |
336 | ||
1da177e4 LT |
337 | static int __init xpram_setup_blkdev(void) |
338 | { | |
339 | unsigned long offset; | |
340 | int i, rc = -ENOMEM; | |
341 | ||
342 | for (i = 0; i < xpram_devs; i++) { | |
3ce66093 MS |
343 | xpram_disks[i] = alloc_disk(1); |
344 | if (!xpram_disks[i]) | |
345 | goto out; | |
3d745ea5 CH |
346 | xpram_queues[i] = blk_alloc_queue(xpram_make_request, |
347 | NUMA_NO_NODE); | |
3ce66093 MS |
348 | if (!xpram_queues[i]) { |
349 | put_disk(xpram_disks[i]); | |
1da177e4 | 350 | goto out; |
3ce66093 | 351 | } |
8b904b5b BVA |
352 | blk_queue_flag_set(QUEUE_FLAG_NONROT, xpram_queues[i]); |
353 | blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, xpram_queues[i]); | |
e1defc4f | 354 | blk_queue_logical_block_size(xpram_queues[i], 4096); |
1da177e4 LT |
355 | } |
356 | ||
357 | /* | |
358 | * Register xpram major. | |
359 | */ | |
360 | rc = register_blkdev(XPRAM_MAJOR, XPRAM_NAME); | |
361 | if (rc < 0) | |
362 | goto out; | |
363 | ||
1da177e4 LT |
364 | /* |
365 | * Setup device structures. | |
366 | */ | |
367 | offset = 0; | |
368 | for (i = 0; i < xpram_devs; i++) { | |
369 | struct gendisk *disk = xpram_disks[i]; | |
370 | ||
371 | xpram_devices[i].size = xpram_sizes[i] / 4; | |
372 | xpram_devices[i].offset = offset; | |
373 | offset += xpram_devices[i].size; | |
374 | disk->major = XPRAM_MAJOR; | |
375 | disk->first_minor = i; | |
376 | disk->fops = &xpram_devops; | |
377 | disk->private_data = &xpram_devices[i]; | |
3ce66093 | 378 | disk->queue = xpram_queues[i]; |
1da177e4 | 379 | sprintf(disk->disk_name, "slram%d", i); |
1da177e4 LT |
380 | set_capacity(disk, xpram_sizes[i] << 1); |
381 | add_disk(disk); | |
382 | } | |
383 | ||
384 | return 0; | |
1da177e4 | 385 | out: |
3ce66093 MS |
386 | while (i--) { |
387 | blk_cleanup_queue(xpram_queues[i]); | |
1da177e4 | 388 | put_disk(xpram_disks[i]); |
3ce66093 | 389 | } |
1da177e4 LT |
390 | return rc; |
391 | } | |
392 | ||
14532095 MH |
393 | /* |
394 | * Resume failed: Print error message and call panic. | |
395 | */ | |
396 | static void xpram_resume_error(const char *message) | |
397 | { | |
2c48c4d6 | 398 | pr_err("Resuming the system failed: %s\n", message); |
14532095 MH |
399 | panic("xpram resume error\n"); |
400 | } | |
401 | ||
402 | /* | |
403 | * Check if xpram setup changed between suspend and resume. | |
404 | */ | |
405 | static int xpram_restore(struct device *dev) | |
406 | { | |
407 | if (!xpram_pages) | |
408 | return 0; | |
409 | if (xpram_present() != 0) | |
410 | xpram_resume_error("xpram disappeared"); | |
411 | if (xpram_pages != xpram_highest_page_index() + 1) | |
412 | xpram_resume_error("Size of xpram changed"); | |
14532095 MH |
413 | return 0; |
414 | } | |
415 | ||
47145210 | 416 | static const struct dev_pm_ops xpram_pm_ops = { |
14532095 MH |
417 | .restore = xpram_restore, |
418 | }; | |
419 | ||
420 | static struct platform_driver xpram_pdrv = { | |
421 | .driver = { | |
422 | .name = XPRAM_NAME, | |
14532095 MH |
423 | .pm = &xpram_pm_ops, |
424 | }, | |
425 | }; | |
426 | ||
427 | static struct platform_device *xpram_pdev; | |
428 | ||
1da177e4 LT |
429 | /* |
430 | * Finally, the init/exit functions. | |
431 | */ | |
432 | static void __exit xpram_exit(void) | |
433 | { | |
434 | int i; | |
435 | for (i = 0; i < xpram_devs; i++) { | |
436 | del_gendisk(xpram_disks[i]); | |
3ce66093 | 437 | blk_cleanup_queue(xpram_queues[i]); |
1da177e4 LT |
438 | put_disk(xpram_disks[i]); |
439 | } | |
440 | unregister_blkdev(XPRAM_MAJOR, XPRAM_NAME); | |
14532095 MH |
441 | platform_device_unregister(xpram_pdev); |
442 | platform_driver_unregister(&xpram_pdrv); | |
1da177e4 LT |
443 | } |
444 | ||
445 | static int __init xpram_init(void) | |
446 | { | |
447 | int rc; | |
448 | ||
449 | /* Find out size of expanded memory. */ | |
450 | if (xpram_present() != 0) { | |
d1c2f892 | 451 | pr_err("No expanded memory available\n"); |
1da177e4 LT |
452 | return -ENODEV; |
453 | } | |
e620c494 | 454 | xpram_pages = xpram_highest_page_index() + 1; |
d1c2f892 MS |
455 | pr_info(" %u pages expanded memory found (%lu KB).\n", |
456 | xpram_pages, (unsigned long) xpram_pages*4); | |
1da177e4 LT |
457 | rc = xpram_setup_sizes(xpram_pages); |
458 | if (rc) | |
459 | return rc; | |
14532095 MH |
460 | rc = platform_driver_register(&xpram_pdrv); |
461 | if (rc) | |
462 | return rc; | |
463 | xpram_pdev = platform_device_register_simple(XPRAM_NAME, -1, NULL, 0); | |
464 | if (IS_ERR(xpram_pdev)) { | |
465 | rc = PTR_ERR(xpram_pdev); | |
466 | goto fail_platform_driver_unregister; | |
467 | } | |
468 | rc = xpram_setup_blkdev(); | |
469 | if (rc) | |
470 | goto fail_platform_device_unregister; | |
471 | return 0; | |
472 | ||
473 | fail_platform_device_unregister: | |
474 | platform_device_unregister(xpram_pdev); | |
475 | fail_platform_driver_unregister: | |
476 | platform_driver_unregister(&xpram_pdrv); | |
477 | return rc; | |
1da177e4 LT |
478 | } |
479 | ||
480 | module_init(xpram_init); | |
481 | module_exit(xpram_exit); |